This invention relates to an element for opening and/or closing doors, gates or windows, comprising a first part designed to operate a closing mechanism by rotation around a rotation axis, and a second part, rotatable around substantially the same axis, and designed to be coupled in its rotary motion to the first part.
This element could, for instance, take the form of a rotary knob, a rotatable part, handle and/or lever which may be used to open and/or close a door, gate or window.
Elements to operate closing mechanisms are known and are most of the time rotatable, against the force exerted by a spring, in order to remove a pin and suchlike extending sideways, from a recess in a door post and suchlike in order to open the gate or the door in accordance with the principle of the mechanism with which most inner doors are provided.
However, doors and gates provided with the elements described above are easy to be opened by children. Because of this, these elements have the disadvantage that they cannot be used to prevent children from entering by accident.
The disadvantage described above is partly resolved in the publication of the German patent DE 199 57 697. There an element was disclosed, in the form of a rotary knob, which must be pushed forward against the force exerted by a spring, before the door can be opened by a rotary motion of the knob, in order to prevent doors from being opened by children.
However, the knob described in DE 199 57 697 has the disadvantage that it is only possible to open doors in one direction. At the same time the possibility still exists that children may open the door by accident by leaning against the knob and turning it.
This problem was partially addressed by an element in the form of a door handle described in German patent DE 803 698. This handle comprises a first part designed to operate a closing mechanism by rotation around a rotation axis, a second part which is rotatable around substantially the same axis, and a connecting part, coupled to said second part in rotation around said axis. The connecting part is movable in the direction of said rotation axis between a first position, in which it is substantially freely rotatable around said axis with respect to said first part, and a second position, in which it is substantially coupled to said first part in rotation around said axis. A resilient element is provided which urges the connecting part towards the first position. The second part comprises a push button which can be arranged at a substantial angle with respect to said rotation axis, and which, when pushed, displaces said connecting part from said first position towards said second position. Since said push button no longer needs to be aligned with the rotation axis, this handle is suitable for use in doors that open by pulling as well as by pushing, and is less subject to accidental opening.
However, the door handle of DE 803 698 presents some drawbacks. Although it presents two push buttons, only one of them is functional and displaces the connecting part towards said second position when pushed. The other push button is a dummy button. Since the connecting part and the second part are freely rotatable while the connecting part is in said first position, a user will not have a reliable positional clue as to which one of the two push buttons is the functional button, and which one is the dummy button. Furthermore, the free rotation of the second part may place the functional button in a difficult-to-reach position. Because of this, even an authorized user may lose valuable seconds when trying to open the door, gate or window in an emergency. Moreover, none of the described mechanisms is directly suitable to be used with several functional push buttons.
An object of the present invention is that of providing a child-safe opening and/or closing element which nevertheless does not unnecessarily delay its operation by adults.
A further object of the present invention is that of providing a child-safe opening and/or closing element that can be actuated comfortably and without excessive effort.
To provide this, the element for opening and/or closing doors, gates or windows according to the present invention comprises:                a first part designed to operate a closing mechanism by rotation around a rotation axis;        a second part which is rotatable around substantially the same axis;        a connecting part, which is coupled to said second part in rotation around said axis, and movable with respect to the first part along said axis, between a first position, in which it is substantially freely rotatable around said axis with respect to said first part, and a second position, in which it is substantially coupled to said first part in rotation around said axis; and        a resilient element urging said connecting part towards said first position; wherein        the second part comprises at least two push buttons arranged at a substantial angle with respect to said rotation axis, and wherein any one of said at least two push buttons, when pushed, displaces said connecting part from said first position towards said second position.        
By carrying out the element in such a manner, it has the advantage that doors, gates or windows may be opened in different directions, preferably by pulling, pushing or sliding. At the same time two operations, namely pushing a push button and giving a rotary motion to the element, have to be performed in order to open a door and suchlike, because of which it will become practically impossible for children to open a door by accident. Nevertheless, the element will still be easily actuated by an adult, in particular in case of emergency, without undue exertion, by pressing any one or several of the buttons and rotating the second part.
In a preferred embodiment of the element according to the invention, each push button comprises a wedge surface inclined with respect to said rotation axis, and said connecting part comprises corresponding surfaces, so that, when any one or several of said push buttons is pushed, said wedge surface will push said connecting part from said first position towards said second position.
In a more particular preferred embodiment of the element according to the invention, the said connecting part and said first part form a dog clutch which closes when said connecting part reaches said second position. This ensures the transfer of the rotary motion of the second part to the first part.
Preferably, the push buttons are located at the outer circumference of the second part. By designing the element in such a manner, doors may be opened independently from the position of the element.
Preferably a total force of at least 25 Newton has to be exerted on one or several push buttons in order to make the said bulges engage the said recesses. In a more particular embodiment, this total force amounts to 50 Newton.
In a preferred embodiment of the element according to the invention, the said element is made of synthetic material or metal such as, for instance, aluminium or stainless steel.
In a most preferred embodiment of the element according to the invention, the said element is a rotary knob.